01 - Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
02 - In a bowl, toss halved baby potatoes with 1 tablespoon olive oil, 1/2 teaspoon paprika, 1/4 teaspoon salt, and 1/4 teaspoon pepper. Spread evenly on the baking sheet.
03 - Roast potatoes for 15 minutes.
04 - While potatoes are roasting, combine chicken breasts, 1 tablespoon olive oil, remaining paprika, garlic powder, oregano, remaining salt and pepper, and lemon juice. Let marinate for 10 minutes.
05 - Add red bell pepper and red onion to the potatoes. Toss gently, then return to the oven and roast an additional 15 minutes or until potatoes are golden and chicken is ready to cook.
06 - Heat a grill pan or skillet over medium-high heat. Grill chicken for 5-6 minutes per side, or until cooked through and juices run clear. Rest chicken for 5 minutes, then slice.
07 - Arrange spinach leaves in bowls. Top with roasted potatoes, grilled chicken slices, roasted peppers and onion, and cherry tomatoes.
08 - Garnish with parsley and serve with lemon wedges, if desired.